Running ahead of the pack who want to head the Justice Department's Criminial Division are a New York lawyer who served the Ford administration as the number three man in the division and a California district attorney who helped to prosecute the Black Panthers.

The two candidates are Rudy Guiliani, a partner in the New York law firm of Patterson, Belknap, Webb & Tyler, and D. Lowell Jensen, the district attorney of Alameda County, Calif., who prosecuted Huey Newton in 1968 and gave the evidence to the grand jury that indicted Eldridge Cleaver and Bobby Seale the same year.

Administration sources say both men have been approached about the job, which is the third-ranking job at Justice and in many respects the toughest. Among the many tasks assigned the Criminal Division are the fights on organized crime, white-collar crime, public fraud and corruption and drug traffic. A dark-horse candidate: Samuel Skinner, a partner in the Chicago law firm of Sidley & Austin, who was cheif U.S. attorney in Chicago from 1975 to 1977.

All three men were described as "bright, able and conscientious" and well-schooled in criminal law, although sources conceded that Jensen was not as familiar with federal criminal law as the other two. "His background is California state criminal law," says one source, "but there is nobody in California as well-versed in that law as Jensen."

Guiliani has been described as thorough and dogged, a man of "extreme good judgement." Those who know him well relate a favorite anecdote: When he summed up the government's abuse-of-office case against former New York representative Bertram Podell, Podell stood up in the witness stand and said: 'I'm convinced. I plead guilty."